Fairy tern prospects brighten as chick numbers rise

Two fairy tern chicks were hatched at Te Arai this season. Photo, Ayla Wiles.

After a five year battle, the controversial weir at Te Arai stream is on the way out. Photo, Heather Rogan

Prospects for the survival of New Zealand’s most endangered native bird look more promising, following an uptick in the number of birds hatched this breeding season and the partial removal of a controversial weir.

So far this season, eight New Zealand fairy tern have hatched – five in Mangawhai, two at Te Arai  and one at Pakiri.

Unfortunately, the parents of the Te Arai chicks have unexpectedly disappeared and one of their chicks has since died. The remaining chick is still learning to fly and being closely monitored by Department of Conservation (DOC) rangers.

There are estimated to be only about 40 fairy tern in existence and last year only two chicks in the entire country survived long enough to start flying.

New Zealand Fairy Tern Charitable Trust convener Heather Rogan says the increase in fairy tern numbers probably reflects favourable weather conditions and the fact that Mangawhai Harbour is recovering from the disturbance caused by mangrove removal. Last year, no chicks were fledged from Mangawhai.

The ongoing battle against predators has also helped. Since September, a team of six DOC rangers and numerous community volunteers have been trapping predators and fencing off nesting sites to prevent birds being disturbed by humans.

Rangers and volunteers continue to monitor nests during the remainder of the breeding season.

Ms Rogan is also delighted that work commenced last month to dismantle a weir on Te Arai stream that blocked the passage of fish, which the fairy tern depend on for food.

The weir was originally installed by developer Te Arai North Limited (TANL) to facilitate the extraction of water for the exclusive Tara Iti golf course.

TANL long-denied the weir impeded fish passage, but last November the Environment Court ruled otherwise and said TANL, Auckland Council, DOC and Land Information New Zealand (which owns the stream bed) should resolve the issue as “a matter of utmost urgency”.

Work on removing the weir started last month. The work will be completed in stages to avoid too much disruption during the sensitive breeding season. It’s expected the weir will be gone completely by April.

Ms Rogan says the New Zealand Fairy Tern Charitable Trust was pleased the Environment Court decision had a positive outcome, but adds the trust has been campaigning against the weir for five years, and it should have been removed much earlier.

Once widespread throughout the North Island, the fairy tern now has only a handful of nesting sites in New Zealand. These are at Papakanui Spit, Pakiri, Mangawhai, Waipu and Te Arai.